If a person scratches up a car (say like scratches an obscene word on the trunk of the car) and his fellow partner in vandalism sets the car on fire, would the scratches still be visible or would the fire melt off the paint? If he uses a key to scratch up the car, would the key have the paint of the car on it? Would their clothes smell of the accelerant or the fire they started? Many thanks for your help.
paint scratches and arson
- Thread starter Littlebit66
- Start date
Depends on how hard they press.
Could have paint on the key, but might also fall off quite soon, or transfer to pocket.
Petrol and diesel smell can hang around a bit - spill a bit on the outside of a fuel can you will smell it in the car, get it on your hands, ditto.
Part of the answer lies with the volatility of the liquid and the ambient temperature and breeze. Or in other words, how fast it can evaporate and how much the conditions favour it evaporating. Hot sunny day with breeze vs below freezing and still.
In terms of detection on clothes after a period of time - don't know exactly. Will also depend on the concentration needed for whatever the method of detection is.
Can't give you more forensically detailed answers than that.
Could have paint on the key, but might also fall off quite soon, or transfer to pocket.
Petrol and diesel smell can hang around a bit - spill a bit on the outside of a fuel can you will smell it in the car, get it on your hands, ditto.
Part of the answer lies with the volatility of the liquid and the ambient temperature and breeze. Or in other words, how fast it can evaporate and how much the conditions favour it evaporating. Hot sunny day with breeze vs below freezing and still.
In terms of detection on clothes after a period of time - don't know exactly. Will also depend on the concentration needed for whatever the method of detection is.
Can't give you more forensically detailed answers than that.
Automotive paint is typically three layers: top coat (usually a clear coat), colour layer, and a primer base coat. If the scratch is deep enough to penetrate all three layers and contact the base metal (or fiberglass, carbon fiber, etc.) there is a very good chance the scratch will still be discernible etched into the surface of the base material (assuming sufficient pressure in administering the scratch).
In your scenario it would have to be metal of some type to withstand the heat of a petroleum initiated fire - a sufficient gauge of sheet steel would work. I'd stay away from aluminium because it will lose its structural integrity (melt) at 1,221*F/660.3C, temps that are not unusual in vehicle fires. Steel can withstand about twice that temperature.
http://www.engineeringtoolbox.com/melting-temperature-metals-d_860.html
In your scenario it would have to be metal of some type to withstand the heat of a petroleum initiated fire - a sufficient gauge of sheet steel would work. I'd stay away from aluminium because it will lose its structural integrity (melt) at 1,221*F/660.3C, temps that are not unusual in vehicle fires. Steel can withstand about twice that temperature.
http://www.engineeringtoolbox.com/melting-temperature-metals-d_860.html
I'm not sure who's looking at this after the fire so it's hard to tell exactly what's going to show up. It's hard to put enough pressure on a key to press through all three coats of paint. (These are thicker coats of paint then normal. Primer is a dip and the others are applied heavy.) A flat screw driver is more likely to leave a scratch. The fire doesn't melt off the paint. Instead the paint burns in the fire.
Note that the pavement under the car will have some damage from the heat of the fire.
Little chips of paint will stick to whatever scratches the paint. These can be seen with a microscope for several hours to a few days afterwards. Depending upon the surface pitting of the key paint chips might not be easily cleaned.
A good accelerant for a car fire is charcoal lighter fluid. Depending upon the length of burn, a fire in the engine compartment might not reach the cabin and vice versa. Engine compartments tend to be easy to light, but don't have a lot of fuel to keep the fire burning. Tires are what will really keep a car fire going. The gas tank will most likely vent rather then explode.
Open or break the windows for maximum effect. The front and rear bumpers may blow off from the heat and travel up to 50 yards from the car. This is because of the cylinders used for reducing bumper damage. These cylinders can also blow off a hatchback door.
It takes about five minutes for a car to really get going.
Best of luck,
Jim Clark-Dawe
Note that the pavement under the car will have some damage from the heat of the fire.
Little chips of paint will stick to whatever scratches the paint. These can be seen with a microscope for several hours to a few days afterwards. Depending upon the surface pitting of the key paint chips might not be easily cleaned.
A good accelerant for a car fire is charcoal lighter fluid. Depending upon the length of burn, a fire in the engine compartment might not reach the cabin and vice versa. Engine compartments tend to be easy to light, but don't have a lot of fuel to keep the fire burning. Tires are what will really keep a car fire going. The gas tank will most likely vent rather then explode.
Open or break the windows for maximum effect. The front and rear bumpers may blow off from the heat and travel up to 50 yards from the car. This is because of the cylinders used for reducing bumper damage. These cylinders can also blow off a hatchback door.
It takes about five minutes for a car to really get going.
Best of luck,
Jim Clark-Dawe
If you want to have the word visible, why not "write" it with the accelerant and set the fire? Unless the goal is to completely destroy the car, that is.
I'm looking for ways in which the available evidence at the scene of the crime doesn't prove the guilt of the person who's arrested for the arson. The beginning plot of my WIP is that 3 teens plan to vandalize a hated teacher's car and make it look like another classmate (my MC) did it by deliberately leaving behind the MC's gymbag/bookbag. The plan works and the MC is arrested & jailed, since the MC did have an argument with the teacher, has no alibi, he's a minority, and the police do a sloppy job of investigating. When a couple of years later the evidence is re-examined by a new detective working on the case, he notes that there's no smell or evidence of the lighter fluid on the MC's clothes(not sure if the fluid would still linger on clothes for that long in real life), no car paint on his house keys, none of his prints are at the scene, plus a partial print on the can of lighter fluid is that of one of the teens who originally started the fire. The one teen confesses his part of the crime and gives up the names of the other two but dies before he can testify in court against the other two.
In terms of a solvent lingering on clothes - you could test it yourself - but be very careful.
As I said earlier, it depends on which solvent and what happens next on the clothes. So if you bought a can of lighter fluid and say a set of cotton dishcloths. You would need to do this somewhere safe - as in if it catches fire it doesn't matter and no-one could approach them and get hurt.
You could then put a measured amount on each cloth and start the clock. If you have one cloth under another cloth (to represent putting a jacket on), one just lying on the ground, another waving from a washing line. That would give you a spectrum of conditions - but wouldn't give you anything that would represent a warm human body under the clothes.
So at that level, you would have a measure of the length of time after putting that solvent on the cloth that YOU can still smell the fluid.
However - different people have different sensitivities to different smells and it also doesn't give you any measure of what could be detected by lab equipment.
I suspect you need to read books on arson by arson investigators as that would give you real life scenarios on what can and cannot be detected after a period of time. It would also be safer than playing with lighter fluid.
As I said earlier, it depends on which solvent and what happens next on the clothes. So if you bought a can of lighter fluid and say a set of cotton dishcloths. You would need to do this somewhere safe - as in if it catches fire it doesn't matter and no-one could approach them and get hurt.
You could then put a measured amount on each cloth and start the clock. If you have one cloth under another cloth (to represent putting a jacket on), one just lying on the ground, another waving from a washing line. That would give you a spectrum of conditions - but wouldn't give you anything that would represent a warm human body under the clothes.
So at that level, you would have a measure of the length of time after putting that solvent on the cloth that YOU can still smell the fluid.
However - different people have different sensitivities to different smells and it also doesn't give you any measure of what could be detected by lab equipment.
I suspect you need to read books on arson by arson investigators as that would give you real life scenarios on what can and cannot be detected after a period of time. It would also be safer than playing with lighter fluid.
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I think he's clear. There certainly wouldn't be any smell of lighter fluid on the clothes a couple of years later. And you worked out the fingerprints. But it would be a careless arsonists who would get accelerant on his clothes.
Jim, what's your take on dying declarations/confessions - would that not constitute a potential admissibility exception?
(I realize Littlebit66 didn't mention whether or not any corroborative facts were contained therein, so let's assume there were none.)
(I realize Littlebit66 didn't mention whether or not any corroborative facts were contained therein, so let's assume there were none.)
If the statement was made when the person is dying or believes he is dying, and he is of the right cultural background (there are some cultures where you lie in that circumstance), then a dying declaration is admissible as a hearsay exception and would come probably come in.
However, if the person makes a statement, then dies, and did not realize he was dying at the time of the statement, it doesn't come in, even if the statement is taken as sworn testimony.
The US Constitution and many state constitutions contains a right to confront your accuser. Dying declarations get in usually. But when a prosecutor tries to get in a statement made prior to dying, outside the scope of a dying declaration, it usually doesn't go well. Even though the defendant is probably the person who arranged the witness's untimely demise.
Best of luck,
Jim Clark-Dawe
Thanks, Jim... You're right, of course. I overlooked the apparent fact that there was a time gap between the confession and the demise of the confessing suspect.
Hi Jclarkdawe, oops, sorry, I forgot to mention earlier that my original plan was to set the story approximately around 1965, with the teens around the ages of 17 and 18 years old, the accused 17 years old.
In answer to your comment "Is the kid's attorney dead? Is the judge dead? Is the appeals court dead? This is not legally sufficient to get a convince. Proof must be beyond a reasonable doubt and this doesn't come close. Have an "eye witness" testify.
According to research on the juvenile justice system, before two US Supreme court cases in 1966 and 1967 juveniles were not entitled to key elements of due process such as a right to legal consul, the right to confront or cross exam witnesses, or even notices of the charges against them, as it happened in the '67 Gault case. It wasn't until 1970 Winship case that usually for a conviction in juvenile court, all you needed for a guilty verdict was a "preponderance of the evidence" meaning that the available evidence makes it more likely than not to that the person committed the crime, instead of the prosecutor having to have evidence of "proof beyond a reasonable doubt" in criminal cases involving adults. The original reasoning was that kids and teens under the age of 17/18 (depending on the state) should not be treated as harshly as adults, so their cases would be treated as civil cases, under a more informal relaxed meeting with a judge. The goal was to rehabilitation for children and the belief that a judge would focus on doing whatever was in the best interests of the child. Of course, a judge could also decide to send the offender to a reformatory institution, which in some notorious cases as the ones in Florida or California, were as dangerous adult prisons.
Following the literary advice of "do terrible things to your main character for an interesting story", the legal guardian of the accused decides not to get an attorney for him since he would prefer to get him locked up in order to take control of the family assets (the parents in the story are dead/incapacitated).
In answer to your comment "Is the kid's attorney dead? Is the judge dead? Is the appeals court dead? This is not legally sufficient to get a convince. Proof must be beyond a reasonable doubt and this doesn't come close. Have an "eye witness" testify.
According to research on the juvenile justice system, before two US Supreme court cases in 1966 and 1967 juveniles were not entitled to key elements of due process such as a right to legal consul, the right to confront or cross exam witnesses, or even notices of the charges against them, as it happened in the '67 Gault case. It wasn't until 1970 Winship case that usually for a conviction in juvenile court, all you needed for a guilty verdict was a "preponderance of the evidence" meaning that the available evidence makes it more likely than not to that the person committed the crime, instead of the prosecutor having to have evidence of "proof beyond a reasonable doubt" in criminal cases involving adults. The original reasoning was that kids and teens under the age of 17/18 (depending on the state) should not be treated as harshly as adults, so their cases would be treated as civil cases, under a more informal relaxed meeting with a judge. The goal was to rehabilitation for children and the belief that a judge would focus on doing whatever was in the best interests of the child. Of course, a judge could also decide to send the offender to a reformatory institution, which in some notorious cases as the ones in Florida or California, were as dangerous adult prisons.
Following the literary advice of "do terrible things to your main character for an interesting story", the legal guardian of the accused decides not to get an attorney for him since he would prefer to get him locked up in order to take control of the family assets (the parents in the story are dead/incapacitated).
I was thinking that when the detective/police find the partial print of one of the teens on the can and confront him with the evidence, the teen does end up admitting his part of the arson (he felt guilty after the incident and figures since he's dying of cancer he might as well do the right thing) and agrees to appear in court to clear the main character. After the MC is cleared, they would like to have the teen testify if they arrest the other 2 teenagers but he dies before they can determine if they have enough evidence to prosecute. Since the witness is dead, there is no one a defense attorney can cross examine so therefore no case.
What made the arson incident worse is that during the torching of the car, they accidently lit the garage/part of the house on fire (but the teacher/firefighters was/were able to put the fire out so no one was hurt) so the arson was upgraded from a second degree felony (damage of property) to a 1st degree felony (damage to a dwelling, whether occupied or not). Plus the teens who actually did it were 18 years of age which would legally make them adults.
With the caveat that there were some states, under their Constitutions, that provided justice to juveniles in the 1960s that was equal to adult justice, in many states LittleBit is correct. Even today, you can see some bending of the rules in juvenile cases, although the bending is now solely in the direction of benefiting the kids.
Arson is one of the worst type cases for forensics. Confessions are frequently the only way to get a conviction. So very definitely a dead witness/suspect who made a statement ends the case.
Best of luck,
Jim Clark-Dawe
Arson is one of the worst type cases for forensics. Confessions are frequently the only way to get a conviction. So very definitely a dead witness/suspect who made a statement ends the case.
Best of luck,
Jim Clark-Dawe
Hi Jim, thanks for the boost and advice! For me one of the hardest yet enjoyable parts of working on my outline for the plot is making sure the forensic and legal details are plausible for the story yet accurate to the decade where the story is set. I sometimes wish I could set the story in this current decade but I worry that it could change the plot entirely.