found a house with two liens how should i approach

[Joy Sanchez]

hey everyone, 

i recently moved to east los angeles, california from long beach . i found a house that looks pretty beat up. i asked one of the locals and they said the couple that lives there inherited the house and has had the police there a few times. i looked into the property and there are two liens , one for drugs found and one for a failure of inspection. id like to approach and see if they are interested in selling. my first thought was go door knock and make conversation in person, due to the fact that there is a lot of people at that house partying often i figured that might not be a good idea since investors are not very well liked in this neighborhood. so im writing them letters.  im thinking about sending them a letter a week in both english and spanish. is there anything else i could look into that would give me more of an insight to see if they would be motivated sellers or not ? any advice ? 

thank you all in advance . cheers