Inspect all candy: Tampering is rare, but the LAPD recommends you throw away any candy that is not properly sealed, or that looks spoiled.
"[Follow] the age-old proverb of 'You don't eat anything that you receive on Halloween until your parents have a look at it,' until you can clearly inspect it," said LAPD Narcotics Enforcement Detective Robert Holcomb.
Parents were also advised to be on alert for pre-packaged marijuana-laced candy.
"It could be easily confused with real candy. It's all illicitly manufactured. It all contains varying degrees of THC, the active ingredient in marijuana. That can be considered poisonous if young children ingest it," said Holcomb.
Halloween is one of the most dangerous nights to drive, according to the LAPD.
"Safety is number one," said LAPD Captain Ivan Minsal. "[Kids] run between cars, run across the street to get that trick-or-treat, so we just need to be extra vigilant in our safety while we're driving out there going to and from work."
"Take a moment. Don't be in such a hurry to get home tonight. Pay attention to the surroundings. We don't want to have any fatalities or injuries tonight," said Minsal.
Trick-or-treaters and parents are also reminded to be cautious of traffic.
Police also asked the driving public to turn headlights on early and drive at least 5 mph under the speed limit in residential areas.