Del. Code Ann. tit. 21, § 4403
The police or the Department of Safety and Homeland Security causing the removal of an abandoned vehicle shall immediately ascertain the identity of any person or persons holding a lien against said vehicle. Within 5 days of the removal of the vehicle, the State Police, other police agencies, New Castle County Code Enforcement Constables or the Department shall cause a written notice to be mailed to the registered owner of the vehicle removed and lien holders stating:
If the address of the owner of the vehicle cannot be ascertained by the exercise of reasonable diligence, then the notice provided by this section shall not be required to be given.
21 Del. C. 1953, § 4403; 55 Del. Laws, c. 173; 58 Del. Laws, c. 119, § 5; 66 Del. Laws, c. 236, § 4; 74 Del. Laws, c. 110, § 93; 75 Del. Laws, c. 333, § 2